The Green Surge That Nobody Saw Coming: How Labour Lost Lewisham, Lambeth, and Nicola Sturgeon's Old Seat in a Single Night

While Reform UK’s gains dominated the headlines after the 7 May local elections, the Green Party’s results may prove equally transformative for British politics.

The Greens gained 297 councillors and took control of four councils. But the raw numbers understate the significance of where those gains occurred and what they mean for Labour’s progressive flank.

In London, the Greens took control of both Lewisham and Lambeth — two inner-London boroughs that had been Labour strongholds for decades. Green candidate Liam Shrivastava won the Lewisham mayoralty. In Norwich, the Greens took overall control of the city council.

The leader of Camden Council — the borough that encompasses Prime Minister Keir Starmer’s Holborn and St Pancras constituency — lost his seat to a Green candidate. The symbolism was impossible to miss.

In Scotland, the results were historic. The Greens won a seat in Edinburgh Central, unseating SNP stalwart Angus Robertson — one of the highest-profile figures in Scottish nationalism. In Glasgow Southside, the Greens took what had been Nicola Sturgeon’s constituency seat during her tenure as First Minister.

In Wales, Green leader Anthony Slaughter won one of six seats in the Caerdydd Penarth constituency, bringing the party its first ever seat in the Senedd.

ITV News election analyst Professor Jane Green identified a critical dynamic: even in areas where Reform appeared to be taking seats directly from Labour, the underlying cause was often a split in the progressive vote. Labour supporters were moving to the Greens, allowing Reform to come through the middle under first-past-the-post.

The Electoral Reform Society’s analysis highlighted the distorting effects of the voting system on Green representation. In Hammersmith and Fulham, the Greens won 18.6% of the vote but received no seats at all. In Barking and Dagenham, 21.8% of the vote translated to just 7.8% of seats. But in Lewisham, 42% of the vote delivered 74.1% of seats.

The Green surge has been attributed in part to the leadership of Zack Polanski, who took over the party in 2025. Under his leadership, the Greens have positioned themselves as the primary progressive alternative to Labour — particularly on issues where Starmer’s government has drawn criticism from the left, including the Gaza conflict, welfare reform, and climate policy.

The results place Labour in an unprecedented strategic dilemma. The party is simultaneously losing voters to Reform on its right flank and to the Greens on its left. Under first-past-the-post, this two-front war is devastating: it allows both Reform and the Greens to win seats that Labour would hold under a proportional system, while Labour’s remaining vote is inefficiently distributed.

For the Greens, the question is whether these local government gains can be translated into Westminster seats at the next general election. Their 2026 results suggest a party that has moved beyond protest voting into serious electoral competition — at least in urban areas where progressive voters have lost faith in Labour.